Optimizing a Multi-State Cold-Standby System with Multiple Vacations in the Repair and Loss of Units

A complex multi-state redundant system with preventive maintenance subject to multiple events is considered. The online unit can undergo several types of failure: both internal and those provoked by external shocks. Multiple degradation levels are assumed as both internal and external. Degradation levels are observed by random inspections and, if they are major, the unit goes to a repair facility where preventive maintenance is carried out. This repair facility is composed of a single repairperson governed by a multiple vacation policy. This policy is set up according to the operational number of units. Two types of task can be performed by the repairperson, corrective repair and preventive maintenance. The times embedded in the system are phase type distributed and the model is built by using Markovian Arrival Processes with marked arrivals. Multiple performance measures besides the transient and stationary distribution are worked out through matrix-analytic methods. This methodology enables us to express the main results and the global development in a matrix-algorithmic form. To optimize the model, costs and rewards are included. A numerical example shows the versatility of the model.

Nurture by Tetris: On the Ideological Foundations of the Soviet Computer Game

The authors attempt to speculatively reconstruct the concept of the “So­viet computer game”. They propose to consider gaming practices associ­ated with computers as a derivative of the accepted ideological guidelines that accompany the Soviet project of machine modernization. Within this framework, the concept of the Soviet computer game appears as an unre­alized historical alternative to the normative game design that has devel­oped in countries with market economies. Despite the industry — or the electronic entertainment market — not having had the time to be properly established in the USSR, there were a number of discursive attitudes re­garding the game as such, and the gaming function of computing devices in particular. Even early Soviet pedagogical theories assumed that “playing like a Soviet” involves performing activities structurally similar to labor, where the player becomes part of production. Later, cybernetic discourse, through game theory, indicated the possibility of formalizing any prag­matic activity as a game model; with the advancement of programming, the pragmatics of digital gaming as a way of educating and solving utili­tarian tasks was developed. Based on the memoir archive of Soviet cyber­netics, and publications in the late-Soviet press, the authors demonstrate that the Soviet computer game was not seen an entertainment product, but a representative model for solving problems in an algorithmic form. Thus, the article is not about specific games that could be called Soviet, but about the logic that guided and set the tone for the interpretation of certain computer-game phenomena in the USSR.

Optimal Task Assignment in Distributed Systems through Greedy algorithm

A distributed processing environment consists of one or more applications spread over several computers. These computers may be geographically separated from one another. The applications may be executed on different platforms using different operating systems and telecommunication protocols. In short, a distributed operating environment offers a variety of information system solutions regardless of the location of the user, user’s operating system or the equipment using by user. Performance enhancement of the distributed networks is a major and challenging problem for the researchers. In this paper, algorithm designed, have to allocate m tasks to n processors (m>n) in the environment of distributed processing. These m tasks are to be assigned on the n processors of system through Greedy algorithm of task scheduling. The starting time and finishing time of the processing of a task is considered and denoted by Si and Fi where i= 1, 2, 3, 4, 5…… m. In order to evaluate the optimal time, present algorithm obtains the set of assigned and on assigned tasks. Based on these sets allocation has been made. The method is presented into algorithmic form and several sets of input data have been implemented to test the effectiveness of the algorithm.

PSeInt Technological tool to develop logical-mathematical intelligence in structured computer programming

Information and Communication Technologies (ICT) have an increasing influence on the way of communicating, learning and life; and that the challenge is to use these technologies effectively so that they serve the interests of the students as a whole and of the entire educational community as didactic strategies to support the students, in their arduous task of learning topics related to the development of the logic of computer programming, since for them it is a factor that makes it difficult to solve problems in algorithmic form, independently of any programming language. In the search to improve the teaching-learning process in the fundamentals of the logic of computer programming, the present work aims to describe the experience where the first semester students of the Computer Systems Engineering of the Technological of Advanced Studies of the East of the State of Mexico (TESOEM) learned to develop their skills to understand such logic, necessary to solve problems in algorithmic form using a psedolanguage as a pseudocode, where the PseInt program was used as an educational support tool significantly influencing the understanding of this logic.

Stepping Stones to Inductive Synthesis of Low-Level Looping Programs

Inductive program synthesis, from input/output examples, can provide an opportunity to automatically create programs from scratch without presupposing the algorithmic form of the solution. For induction of general programs with loops (as opposed to loop-free programs, or synthesis for domain-specific languages), the state of the art is at the level of introductory programming assignments. Most problems that require algorithmic subtlety, such as fast sorting, have remained out of reach without the benefit of significant problem-specific background knowledge. A key challenge is to identify cues that are available to guide search towards correct looping programs. We present MAKESPEARE, a simple delayed-acceptance hillclimbing method that synthesizes low-level looping programs from input/output examples. During search, delayed acceptance bypasses small gains to identify significantly-improved stepping stone programs that tend to generalize and enable further progress. The method performs well on a set of established benchmarks, and succeeds on the previously unsolved “Collatz Numbers” program synthesis problem. Additional benchmarks include the problem of rapidly sorting integer arrays, in which we observe the emergence of comb sort (a Shell sort variant that is empirically fast). MAKESPEARE has also synthesized a record-setting program on one of the puzzles from the TIS100 assembly language programming game.

Reconnoitring computational potentials of the vault-like forms: Thinking aloud on muqarnas tectonics

This study sheds light on a holistic understanding of muqarnas with its historical, philosophical and conceptual backgrounds on one hand and formal, structural and algorithmic principles on the other hand. The vault-like Islamic architectural element, muqarnas, is generally considered to be a non-structural decorative element. Various compositional approaches have been proposed to reveal the inner logic of these complex geometric elements. Each of these approaches uses different techniques such as measuring, unit-based decoding or three-dimensional interpretation of two-dimensional patterns. However, the reflections of the inner logic onto different contexts, such as the usage of different initial geometries, materials or performative concerns, were neglected. In this study, we offer a new schema to approach the performative aspects of muqarnas tectonics. This schema contains new sets of elements, properties and relations deriving partly from previous approaches and partly from the technique of folding. Thus, this study first reviews the previous approaches to analyse the geometric and constructional principles of muqarnas. Second, it explains the proposed scheme through a series of algorithmic form-finding experiments. In these experiments, we question whether ‘fold’, as one of the performative techniques of making three-dimensional forms, contributes to the analysis of muqarnas in both a conceptual and computational sense. We argue that encoding vault-like systems via geometric and algorithmic relations based on the logic of the ‘fold’ provides informative and intuitive feedback for form-finding, specifically in the earlier phases of design. While focusing on the performative potential of a specific fold operation, we introduced the concept of bifurcation to describe the generative characteristics of folding technique and the way of subdividing the form with respect to redistribution of the forces. Thus, in this decoding process, the bifurcated fold explains not only to demystify the formal logic of muqarnas but also to generate new forms without losing contextual conditions.

From Narratives to Algorithms

The static, fragmentary nature of the archaeological record requires us to construct models of past human dynamics. Traditionally, these have been in the form of narratives that can make compelling stories but are difficult to evaluate. Recent advances in numerical and computational modelling offer the potential to create quantitative representations of human systems and carry out experiments in social dynamics that would otherwise be impossible. These new approaches challenge us to learn to conceive of human societies in ways that can be expressed in algorithmic form. Besides making our own explanations more rigorous, integrating quantitative modelling into archaeological practice helps us produce more robust accounts of human systems and their long-term changes that can be more useful to other disciplines and policy-makers than compelling narratives.

Gröbner bases for syzygy modules of border bases

Given an order ideal 𝒪 and an 𝒪-border basis of a 0-dimensional polynomial ideal, it was shown by Huibregtse that the liftings of the neighbor syzygies (i.e. of the fundamental syzygies of neighboring border terms) form a system of generators for the syzygy module of the border basis. We elaborate on Huibregtse's proof and transform it into explicit algorithmic form. Based on this, we are able to exhibit explicit conditions on a module term ordering τ such that the liftings of the neighbor syzygies are in fact a τ-Gröbner basis. Finally, we construct term orderings satisfying these conditions in an explicit algorithmic way.